Detector



Feb. 2 1926. A `v 1,571,901

T. G. MCCLANAHAN DETECTOR Fi led March 29 --1924 INVENTOR THOMAS G. MecL'ANAHAN,

Patented Feb. 2, 1926.

or SEATTLE, WASHINGTON.

f primarios slea'marcn 29,1924. ser1a1N.7c2,'zse.

Tov ally 'it mayco'fnoem:

Be it lknown that I, THOMAS G. MCCLNA# HAN, a citizen-of the United States, and a lresident of :the city of jSeattle, county of KinggyState ofV Washington, have invented certainnew and useful Improvements in cation. Y

' Detectors, of which Athe following isl a sp'ecl` yThis invention Vrelates to improvements in detectorsxforvuse in. connection, with radio receiving equipment, more `particularly to detectors adapted for kuse vvith radio refceivi'ngsets of the crystal type; the prin- `cipal object oftheinvention .being to provide a Vdetectorfof novel constructionv and design, which is compact jin rarrangment, easilyadjusted'andwhich. is equi ped withl a cap or cover whereby the orysta and con- `tact ymember are so protected asfto preclude any'ffp'ossible displacement, accidental or otherwise, ofthe contact member orffc'at Whisker after it h-asonce been properly adjusted with respect to the' crystal. 4

More specifically stated,"`the invention resides inthe provision of a `detectoi` of the above character comprising an insulated base member wherein a crystal Vmay be adjustably and removably held and to which is attached a yieldable member wherein a contact or cat Whisker is mounted for adjustment to any position necessary to bring and retain it in proper touch with a sensitive spot on the crystal.

Other objects of the invention reside in the details of construction of the contact mounting members-and the contact and in the arrangement of the parts making up the device. Y

In accomplishing these and other objects of the invention, I'have provided the irn-V proved details of construction, the preferred forms of which are illustrated in the accompanying drawings, whereinvFig. 1 is a perspective view of a crystal detector constructed in accordance with the present invention, showing the cap or cover member in raised position. 4

Fig. 2 is a similar view with the cap in place and enclosing the crystal and contact.

Fig. 3 is an enlarged plan with the cap removed. j

Fig. 4 is an enlarged, central section of the device V'particularly illustrating the meansy forand manner of mounting .the crystal andcontact. v Fig. 5: isl an underside view tector. Y j, y Y

n Fig. 6 is anlenlarged perspectiveview of the contact and its vyieldable supporting member.' Y

Referring morexfin'detail to the several views of' the drawingsl rofV the de* ber which, inthe present design is substantially of diamond shape, roundedv atethe corners and providedcentrally with .a circular, raised `portion 2 over which a cap 3 is adapted to be removably fitted to protect the crystal and contact member as presently described. At opposite sides of the raised portion are openings through which metal 1, designates a base member ofinsulating j material such as bakelite, fibre or-hard rub- 6&5

eyelets 4 and are..extended and clinched .i

and which are adapted toreceive boltsZ and i 8 therein, asjindicated in4 dotted V.linesv in Figure 4, for lthe purpose-.of fastening the device to a panel 9 and which further serve as the meansV of electrically connecting Vthe eyelets with circuit wires designated at 10 and 11.

' Formed in the base member within the raised portion 2 thereof are two openings 12 and 13, the latter being somewhat greater in diameter than the former and has aV crystal mounting 14 removably fitted there- 1n. The mounting carries the sensitive crystal 15 that is exposed at the upper surface of the mounting. VThe mounting is held removably and adjustably in posltion by engagement therewith of the free end of a spring finger 16 supported bythe eyelet 5; the spring being provided at the mounting end with an opening through which the lower end of the eyelet is extended and clinched thereby holding the spring securely in place yet permitting a rotative movement to one side, 'as indicated in dotted lines in Fig. 5, to permit the removal or placing of the crystalmounting in the opening 13.

Supported from the lower end of the eyelet 4 is a spring finger 18 which, at its free end, has an integral cylin-drically formed portion 19 projecting upwardly through the vertically along the side adjacent the crystal mounting and the edge portions QU and 2l thereof, as shown hest in Figures 5 and 6, and due to the resiliency or' the uietal, there is a normal tendency of the two overlapped parts to spread apart. Provide-d inthe hach portion of the cylindrical member and in the tWo overlapped portions thereof at the saine horizontal level are perfor-ations Q2, see Figure 6, through which the mounting end portion of a contact Wire or cat jwhisker 25 is slidahly and adjastahly held. This contact wire has a portion 2.3 curved upwardly and then downwardly to engage at its end with the crystal l5. The mounting end of the contact may he slipped longitudinally within the perforations to bring the end of the part 25 into proper relation with the crystal and it will he held at any position of adjustment by the pressure in opposite directions thereagainst of the two overlapped portions of the mounting mornber 19.

The finger or spring 18 has a normal tendency to spring downward and this holds the end of the contact Wire firmly in place against the end of the crystal. Should it he desired to re-adjust `the contact, the spring is pressed upwardly so as to Afree the end olf the Contact from the crystal and the Wire adjusted in the mounting 19.

In using the device, the crystal is lirst placed .in position then the Contact Wire is adjusted into contact with a sensitive spot onthe crystal. After this adjustment has been made, the cap 3 is placed in position Where it is held by a friction tight lit and serves to protect the parts against displacelernen? ment and damage from dust or moisture settling thereon.

What I claim as new and desire to secure hy Letters Patent. is:

1. A detector comprising a base `block ol' insulating materiall having openings therethrough one of which is adapt-ed for seat-ing a crystal therein, a spring arm lined to the hloclr and adapted to retain the crystal adjustably and removably in said opening, a second spring arm lined to the block and having a contact supporting means at one end extending through another of the said openings, a Contact wire supported adjustably in said means 'for contact with the crystal and means whereby the spring arms may he connected electrically in a circuit.

il. A device or" the class, described `comprising a base block of insulating material with a pair of openings therein, a crystal mounting fitted adjustably and removably in one ott-he openings to expose the crystal at the top of the block, a pair of spring arms mounted on the under side of the block, one of which `may be moved to a position to retain the crystal in position and the other of which has an upwardly turned end portion extending upwardly and through the other opening in the block, a` contact wire adjustahly mounted in said upturned portion and adapted to be held yieldingly thereby in contact with the crystal and ineans through which circuit connections may he made with the said spring arms.

Signed at Seattle, King County, Washington,` March, 1924. y

THOMAS G. MGCLANAHAN. 

